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Chronic Sinusitis Diagnosis

Sinusitis is an infection in the sinuses, which are air-filled spaces or cavities surrounding the nasal cavity and eyes. Sinusitis—also called a sinus infection—can be acute or chronic. Acute infections generally go away within 10 days. If an infection persists for more than 12 weeks, sinusitis is considered chronic. 

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When functioning properly, the sinuses produce mucus that drains through the nasal passages and, eventually, into the throat, where it is swallowed. Sinusitis occurs when the sinus drainage passages become blocked, allowing mucus to accumulate in the sinuses, where it traps bacteria and may cause an infection. 

Several common conditions can block the sinus drainage passages. Allergies and colds cause inflammation in the soft tissue that lines the nose and sinus cavities, which can block mucus from draining. The nose and sinuses may also be blocked by a deviated septum, which is a displacement of the thin wall that separates the right and left nasal passages, or by swelling of the turbinates, which are bony structures that cleanse and humidify air as it passes through the nasal passages. A blockage may also be caused by nasal polyps, which are soft, noncancerous growths that can develop in the sinus cavities or nasal passages. 

The symptoms of sinusitis mimic those of colds and allergies. These may include a feeling of dull pain or pressure on the face, a headache, thick nasal discharge, congestion, postnasal drip, a runny nose, bad breath, cough, and a loss of the sense of smell.

Types of Chronic Sinusitis

There are four types of chronic sinusitis: allergic, nonallergic, with nasal polyps, and without nasal polyps. In order to determine which type is causing your symptoms and to recommend the most appropriate treatment, your doctor performs a physical exam and asks you about your medical history, including the frequency and severity of your symptoms. He or she then closely examines your nasal passages and sinus cavities to determine if there are signs of obstruction, inflammation, infection, or polyps. 

Diagnostic Tools

Your doctor may recommend certain diagnostic tests to determine the cause of your symptoms. These may include:

Fiberoptic Nasal Endoscopy

Fiberoptic nasal endoscopy is a diagnostic exam that provides detailed images of sinus cavities and nasal passages. It can reveal potential causes and signs of chronic sinusitis, such as inflammation, a slow drainage of mucus from the sinuses, the presence of a deviated septum, enlarged turbinates, or nasal polyps. 

An endoscope is a thin fiberoptic instrument that provides your doctor with a clear, bright image of the entire nasal passage. To perform this procedure, your doctor may first spray the nose with a decongestant to open up the nasal passages and a local anesthetic solution to lessen any discomfort during the procedure. The doctor then inserts the endoscope through each nostril. This procedure lasts just a few minutes and takes place in your doctor’s office. 

During an endoscopy, your doctor may decide to take a mucus or tissue sample for laboratory testing if a bacterial infection is suspected. 

Allergy Test

In order to diagnose chronic sinusitis caused by an allergic reaction, your doctor asks you questions about your medical history, including whether you’ve tested positive in the past for any allergies. If you haven’t had an allergy test and your doctor suspects this may be the cause of the sinus infection, he or she may refer you to an allergist for a simple blood test to detect elevated levels of antibodies in the blood, which indicate an allergic reaction.

CT Scan

A CT scan may be recommended to complement nasal endoscopy if your doctor needs more detail about the extent of a sinus infection and the anatomy of the sinus cavities. CT technology uses X-rays to create a series of detailed, three-dimensional images of your sinuses from a variety of angles. A CT scan can reveal the extent and location of inflammation and polyps in the sinuses that may not be visible during a nasal endoscopy. 

When the type of chronic sinusitis and the cause of the sinus blockage have been determined, our doctors can recommend treatment.

Our Research and Education in Chronic Sinusitis

Learn more about our research and professional education opportunities.